Choose from 10 Options
- $15 for a medicine plant walk for one ($25 value)
- $30 for a medicine plant walk for two ($50 value)
- $39 for an all-day survival skills intensive course for one ($85 value)
- $78 for an all-day survival skills intensive course for two ($170 value)
- $17 for a fire-building workshop for one ($35 value)
- $34 for a fire-building workshop for two ($70 value)
- $17 for a bow-making class for one ($35 value)
- $34 for a bow-making class for two ($70 value)
- $15 for a “Weapons in Nature” weapon-building workshop for one ($25 value)
- $30 for a “Weapons in Nature” weapon-building workshop for two ($50 value)
The Compass: A Magnetic Marvel
Anyone can learn to use a compass to find their way through the woods more reliably—but the science behind it is a little more complicated. Read on to find out why.
A familiar tool to any wilderness adventurer, a compass is simply a magnetized needle fixed upon a pivot point that allows it to swivel with minimal friction. The needle aligns with the Earth’s magnetic field, so labeling one end of it allows you to always know which direction is north—sort of. There are two different points on the globe with equal claim to the name: true north, where the longitude lines on a globe converge and Santa’s castle sits, and magnetic north, where the compass needle points.
The latter point has been drifting westward for as long as humanity has been using compasses to observe it. While there’s a lot we don’t yet know about the Earth’s magnetic field, one recent model accounts for this drift by proposing an uneven rate of cooling in the Earth’s mostly molten iron and nickel core, which would distort the rotation-driven gyres that induce the electric currents making up the geomagnetic field. The difference can set you hundreds of feet off course over a 10-mile hike.
Fortunately, most compass models account for this issue. The most basic do so via an adjustable orienting arrow fixed to the compass base. Fresh off the compass vine, it will be aligned with the big N on the dial, but if you’re navigating anywhere other than the line along which the two north poles happen to converge, you’ll need to adjust it, typically by turning a screw. Maps will include the angle of declination for the area shown—that is, the number of degrees you’ll need to adjust for depending on where you are on the globe. Because of the continual drift of magnetic north, it’s important that your map be relatively recent.
For all the trouble the shifting geomagnetic field causes navigators, it’s actually somewhat weak. Pass a refrigerator magnet over your compass and you’ll see how little loyalty the pole commands from the needle. Therefore, when you’re taking a reading, you’ll want to minimize interference and get away from not only other magnets but also steel and iron hiding out in places such as vehicles and jewelry.